3-Furyl thioesters to impart meaty aroma and taste

ABSTRACT

Methods for altering the organoleptic properties of foodstuffs comprising incorporating with such foodstuffs a small but effective amount of at least one 3-thia furan having the formula:   WHEREIN R1 is C1-C7 straight chain or branched chain alkyl or alkenyl; or R1 is either furyl, thienyl, toluyl, phenyl ethenyl or phenyl; and wherein each of R2, R3 and R4 is the same or different hydrogen or lower alkyl together with compositions containing the 3-thia furans for use in altering such organoleptic properties.

United States Patent Evers et al.

3-FURYL TI-IIOESTERS TO IMPART MEATY AROMA AND TASTE Inventors: WilliamJ. Evers, Atlantic Highlands; Howard H. Heinsohn, Jr., Hazlet; BernardJ. Mayers, Cliffwood Beach; Elizabeth A. Karoll, Old Bridge, all of NJ.

Assignee: International Flavors & Fragrances Inc., New York, NY.

Notice: The portion of the term of this patent subsequent to Aug. 7,I990, has been disclaimed.

Filed: June I1, 1974 Appl. No.; 478,369

Related US. Application Data Continuation-impart of Ser No 386,451 Aug.7.

1973, Pat. No. 3,873,73l.

US. Cl 426/535; 260/3472; 260/3322 C Int. Cl. A23L l/23l Field ofSearch... 260/3472, 332.2 C;

References Cited UNITED STATES PATENTS 5/l972 Evers et al. .f. 426/65 [41 *Nov.4, 1975 FOREIGN PATENTS OR APPLICATIONS 1.283912 8/!972 UnitedKingdom 426/65 Primary Examiner.loseph M. Golian Attorney, Agent, orFirmArthur L. Liberman, Esq.; Harold Haidt, Esq.

[ ABSTRACT Methods for altering the organoleptic properties offoodstuffs comprising incorporating with such foodstuffs a small buteffective amount of at least one 3- thia furan having the formula:

4 Claims, N0 Drawings 3-FURYL THIOESTERS TO IMPART MEATY AROMA AND TASTEThis application is a continuation-in-part of application for US. Pat.Ser. No. 386,451 filed on Aug. 7, I973 and now U.S. Pat. No. 3,873,731.

BACKGROUND OF THE INVENTION The present invention provides methods foraltering the organoleptic properties of foodstuffs by adding to suchfoodstuffs quantities of one or more 3-thia furans and it furtherrelates to compositions adapted to alter the organoleptic properties offoodstuffs.

Artificial flavoring agents for foodstuffs have received increasingattention in recent years. In many areas, such food flavoring agents arepreferred overe natural flavoring agents at least in part because of theuniform flavor that may be so obtained. For example, natural foodflavoring agents such as extracts, essences, concentrates and the likeare often subject to wide variation due to changes in the quality, typeand treatment of the raw materials. Such variation can be reflected inthe end product and results in unreliable flavor characteristics anduncertainity as to consumer acceptance and cost. Additionally, thepresence of the natural product in the ultimate food may be undesirablebecause of increased tendency to spoil. This is particu larlytroublesome in convenience and snack food usage where such products asdips, soups, chips, prepared dinners, canned foods, sauces, gravies andthe like are apt to be stored by the consumer for some time prior touse.

The fundamental problem in preparing artificial flavoring agents is thatof achieving as nearly as possible a true flavor reproduction. Thisgenerally proves to be a difficult task since the magnetism for flavordevelopment in many foods is not understood. This is noteable inproducts having meaty and roasted flavor characteristics. It is alsonoteable in products having vegetablelike and hydrolyzed vegetableprotein-like and aniselike flavor characteristics.

Reproduction of roasted and meat flavors and aromas and vegetable-likeand hydrolyzed vegetable protein-like and anise-like flavors and aromashave been the subject of the long and continuing search by those engagedin the production of foodstuffs. The severe shortage of foods,especially protein foods, in many parts of the world has given rise tothe need for utilizing non-meat sources of proteins and making suchproteins as palatable and as meat-like as possible. Hence, materialswhich will closely simulate or exactly reproduce the flavor and aroma ofroasted meat products and liver products and vegetable products arerequired.

Moreover, there are a great many meat containing or meat based foodspresently distributed in a preserved form. Examples being condensedsoups, dry-soup mixes, dry meat, freeze-dried or lyophilized meats,packages gravies and the like. While these products contain meat or meatextracts, the fragrance, taste and other organoleptic factors are veryoften impaired by the processing operation and it is desirable tosupplement or enhance the flavors of these preserved foods withversatile materials which have either roasted meat or gravy-like orvegetable-like or meat-like or ham-like nuances.

US. Pat. No. 3,666,495 provided materials having such desirable meat,roast meat and roasted fragrance and flavor notes. Such materials areorganic oxygen 2 containing heterocyclics wherein the second carbon atomfrom the oxygen atom contains a sulfur substituent and included 3-thiafuran compounds having the structure:

wherein R R R and R are the same or difi'erent alkyl or hydrogen. Theprocess disclosed in this patent indicated that such furan 3-thiols andalkyl substituted furan 3-thiols can be produced by the reaction of anappropriate dihydro furanone-3- or tetrahydro furanone- 3- with hydrogensulfide in the presence of anhydrous hydrogen chloride at tempertures of60C to l00C. South African Patent No. 69/4539 dated June 26, 1969discloses, for use as intermediates for subsequent reaction withhydrogen sulfide to form flavor compounds, dihydro furyl thioestershaving the structure:

See pages 6 and 7 of the said South African Patent.

Volumn 24 Food Technology" page 535 (May, 1970) [the Gras IV list No.3162] discloses the use as a flavor adjuvant fiirfural S thioacetatehaving the structure:

Nothing in the prior art, however, sets forth implicitly or explicitlythe 3-furyl thioesters of our invention and their unique andadvantageous and unobvious flavor properties.

2,5-dimethyl-3-thio(2-ethylbutyryl) furan 2-methyl-3-thio(2-ethylbutyryl) furan 2,5-dimethyl- 3-thio( 2 -methylbutyryl furan2-methyl-3-thio( 2-me thylbutyryl furan THE INVENTION The presentinvention provides methods for altering the organoleptic properties offoodstuffs which comprise adding to such materials at least one 3-thiafuran. Briefly, the methods comprise adding an amount of at least onethia furan having the formula:

wherein R. is C -C straight chain or branched chain alkyl or alkenyl orR, is furyl, thienyl, toluyl, phenyl ethenyl or phenyl; wherein each ofR R and R is the same or different hydrogen or lower alkyl to afoodstuff to change the organoleptic properties of said foodstuffs. Theinvention also contemplates compositions containing such 3-thia furancompounds.

Preferred 3-thia furans useful in our invention are as follows:

3-thio acetyl furan 2,5-dimethyl-3-thio acetyl furan 2-methyl-3-thioacetyl furan 2,5-dimethyl-4-ethyl-3-thio acetyl furan 2-methyl-3-thioisobutyryl furan 2,5-dimethyl-3-thio isobutyryl furan2,5-dimethyl-3-thio isovaleryl furan 2-dimethyl-3-thio isovaleryl furan2-methyl-3(2-thio furoyl) furan 2,5-dimethyl-3(2-thio furoyl) furan2-methyl-3-thio octanoyl furan 2,5-dimethyl-3-thio octanoyl furan2,5-dimethyl-3-thio benzoyl furan 2,5-dimethyl-3-thio propionyl furan2-methyl-3-thio pivaloyl furan 2,5-dimethyl-3-thio pivaloyl furan2,5-dimethyl-3-thio hexanoyl furan 2-propyl-3-thio acaetyl furan2,5-dimethyl-3-thio( 2-methyl-2-pentenoyl) furan 2,5-dimethyl-3-thiotoluoyl furan 2,5-dimethyl-3-thio cinnamoyl furan 2,5-dimethyl-3-thio(Z-methyl-Z-pentenoyl) furan The novel compounds of our invention may beproduced according to processes which comprise the steps of:

i. providing a Z-ene-l ,4 dione having the structure iii. cyclizing said2-thia substituted 1,4 dione to form a substituted or unsubstituted3-thia furan having the formula:

iv. optionally but only when R;, is acyl or aroyl, hy- 10 drolyzing the3-thia furan to form a 3-mercapto furan having the structure:

wherein R, is straight chain or branched chain alkyl or alkenyl havingfrom 1 up to 7 carbon atoms or R, is either of furyl, thienyl, toluyl,phenyl ethenyl, or phenyl; wherein each of R R and R is the same ordifferent hydrogen or lower alkyl; wherein R is acyl or aroyl; andwherein R is acyl or aroyl different from R R or- [and R may each behydrogen in the event that in step (ii) the 2-ene-l ,4 dione is admixedwith the thio acid having the formula R SH in the presence of an organicbase such as piperidine, pyridine, triethyl amine, quinoline ora-picoline or a mixture thereof.

The 2-ene-l,4 dione may be prepared by reacting2,5-dialkoxy-2,5-dialkyl-2,5-dihydrofuran with a weak acid hydrolysisagent such as 1% aqueous acetic acid under reflux conditions. Theresulting material will be in the case of starting with2,5-dimethoxy-2,5-dimethyl-2,5-dihydrofuran, cis-3-hexen-2,5-dione.

The resulting 2-ene-l,4 dione is then reacted with a thio acid havingthe formula R SH wherein R is either aryl or aroyl.

Examples of such thio acids are:

5 Thioacetic acid Thiopropionic acid Thiobutyric acid Thioisobutyricacid Thio-n-pentenoic acid Thiocinnamic acid Thiobenzoic acid 2-MethylThiobenzoic acid 3-Methyl Thiobenzoic acid 4-Methyl Thiobenzoic acid2,4-Dimethyl Thiobenzoic acid 3,5-Dimethyl Thiobenzoic acid Whether anorganic base is used or not in the reaction with the 2-ene-l,4 dionewith the thio acid having the formula R SH, the 2-ene-l,4 dione can beexemplified as follows:

Compound Name R R R 3-Hexen-2,S-dione Methyl Methyl Hydrogen3-Methyl-3-hexen-2,5 Methyl Methyl Methyl dione 3Methyl-3-hepten-2.5Methyl Ethyl Methyl dione 3-Ethyl-3-hepte n-2 ,5 M ethyl Ethyl Ethyldione 4-Ethyl-4-octen 3,6 Ethyl Ethyl Ethyl dione 3Propyl3hepten-2,5Methyl Ethyl Propyl dione 4-Methyl-3-hep ten-2 ,5 Ethyl Methyl Methyldione 4-Methyl-4-octen-3,6 Ethyl Ethyl Methyl dione 4-Methyl-4-nonen-3,6 Ethyl Propyl Methyl dione 4-Propyl-3-hepten-3,6 Ethyl Methyl Propyldione S-Methyl-S-dec ene-4,7 Propyl Propyl Methyl dione5-Methyl-4-nonen-3,6 Propyl Ethyl Methyl dione 4-Methyl-3-nonen-2,5Butyl Methyl Methyl dione 4Ethyl-3-nonen 2,5 Butyl Methyl Ethyl dione3-Methyl-3-nonen-2,5 Methyl Butyl Methyl dione 3-Propyl-3-nonen 2,5 Methyl Butyl Propyl dione 3-Butyl-3-hexen-2,5 Methyl Methyl Butyl dione4-Octen-3,6-dione Ethyl Ethyl Hydrogen As stated above, R and R can eachbe hydrogen for the purposes of these processes of our invention in theevent that in the reaction of the 2-ene-l,4 dione with the thio acid ofthe formula R SH, an organic base is used. Hence, in addition to theforegoing compounds, the following compounds can be utilized in thereaction with R SH:

Examples of useful organic bases are piperidine, pyridine, quinoline,triethyl amine and a-picoline. In place of such organic bases, radicalinitiators may be used such as benzoyl peroxide or azobisisobutylnitrile. The

reaction may be is carried out in a solvent such as water or an othersuch as diethyl ether or a hydrocarbon such as benzene or hexane orcyclohexane. The reaction may also be carried out without the use of asolvent. The reaction may be is carried out under reflux conditionsalthough temperatures varying from 0 up to C are suitable and will giverise to commercially suitable yields. Examples of reaction products,2-thia substitutedl ,4-di0nes which are formed from the reation of the2-enel ,4 diones with the thio acids having the formula R SH are asfollows:

Z-Thia Substituted 2-ene-l,4 dione R SH Thio Acid l,4 dione ReactionThioacetic acid 4 Thioacetyl-5 ethyl octane3,6-dione 3(4-Methylthiohenzoyl) 2-pentanal-4-one 4Ethyl-4-octene- 3,6-dione2-Pentenal-4-one 4-Methyl-thiobenzoic acid 4-oxo2-heptenal Thioaceticacid The foregoing 2thia substituted 1,4-diones are then cyclized toform substituted or unsubstituted 3-thia furans according to thefollowing reaction:

wherein R, and R are the same or different and are each hydrogen orlower alky; wherein R is either acyl or aroyl and R is hydrogen or loweralkyl. The resulting S-thiafurans (novel compounds of our invention) maybe used as such for their organoleptic properties or they may behydrolyzed and then reacylated or rearoylated to form other acyl thia oraroyl thia substituted furans (other novel compounds of our invention)which have still other organoleptic properties useful for flavoringfoodstuffs.

The cyclization reaction carried out in cyclizing the 2-thia substituted1,4-dione is carried out in the presence of a cyclization agent,preferably, isopropenyl acetate. The cyclization is also carried out inthe presence of such a catalyst as concentrated sulfuric acid, zincchloride, boron trifluoride, aluminum trichloride, and para-toluenesulfonic acid, each of these being acid catalysts. Preferably, the ratioof isopropenyl acetate to 2-thia substituted 1,4 dione is 4 to 5:1. Theratio of acid catalyst to isopropenyl acetate is from 0001 up to 0.05(mole ratio). The cyclization reaction may be run at temperatures ofbetween 25C up to reflux at atmospheric pressure (96C). Still greaterreflux temperatures may be used if the presence is greater thanatmospheric. Furthermore, in place of isopropenyl acetate as acyclization reagent, acetic anhydride or propionic anhydride may beused. Ratios of acetic anhydride or propionic anhydride to 2thiasubstituted 1,4 dione are preferably 4 to 5:] (mole ratio).

In the event that the resulting 3-thia furan is desired to be used as afood flavor additive, the reaction prod- 7 uct is purified byappropriate extraction and distillation techniques. Thus, the following3-thia furans of our invention produced in this manner have usefulorganoleptic properties giving rise to their use as foodstuff flavors asset forth in an illustrative manner in the following table:

Flavor Properties An optional additional step is hydrolysis of the3-thia furan to form 3-mercapto furan having the structure:

R, S H

The hydrolysis reaction is carried out in the presence of strong aqueousbase, for example, sodium hydroxide, potassium hydroxide, sodiumcarbonate, lithium carbonate, potassium carbonate, and lithiumhydroxide. The mole ratio of base to 3-thia furan is preferably 1:1 butmay be as high as 3:1 or as low as 0.01:1. in addition to solely aqueoussolutions of base, mixtures of alcohol (e.g., methanol and ethanol) andwater may be used as solvents in the hydrolysis reaction. The hydrolysistemperature may vary from room temperature to reflux. in the event thatthe basic solution is a solution which is alcoholic (substantiallypurely alcoholic) the alkali metal thiafuran may be formed.

Reacylation of the 3-furan thiol to yield still other acyl thiafurans oraroyl thiafurans is carried out by reaction of the appropriate acyl oraroyl halide with the 3-furan thiol in the presence of an appropriatesolvent such as diethyl ether, tetrahydro furan, or cyclohexane and inthe presence of preferably a strong organic base such as pyridine ora-picoline. Thus, the following table sets forth the several compoundswhich can be conveniently formed having a large number of organolepticproperties giving rise to a wide field of flavor uses:

Name of Compound organoleptic Property 2-Methyl-3-thio -isobutyryl furan2,5-Dimethyl-3-thioisobutyryl furan continued Name of Compoundorganoleptic Property 2,5 Dimethyl-3-thioisovaleryl furanZ-MethyI-B-thio-isovaleryl furan 2-Methyl-3( 2-thiofuroyl) furan 2 .5-Dimethyl-3( Z-thiofuroyl) furan 2-Methyl-3-thio oetanoylfuran 2,5-Dirnethy l- 3-thiooctanoyl furan 2,5-Dimethyl-3-thiobenzoyl furan2-Methyl-34hiopivaloyl furan 2,5 -DimethyI-B-thiopivaloyl furan 2,5-Dimethyl-3-thio-hexanoyl furan 2,5-dimethyl3-thio (2-ethylbutynyl)furan 2-methyl- 3-thio( 2-ethylbutyryl) furan 2,5 dimethyl-3-thio(Z-methylbutyryl) furan 2-methyl-3-thio (2methylbutyryl) furan2,5-Dimethyl-3-thiocinnamoyl furan 2,5'Dimethyl-3-thio(mtoluoyl) furan2,S-Dimethyl-3-thio( 2- methyl-2-pe ntenoyl) furan 0.1 ppm concentrationCreamy cocoa-like sweet aroma. Cocoa powder creamy green flavor at 0.1ppm concentration Green meaty vegetable-like aroma. Green meatyvegetable-like HVP-like flavor at 0,! ppm concentration HVP-like, meatyaroma; HVP- like, liver-like meaty flavor at 0.02 ppm concentrationHVP-like, meaty aroma; HVP- like meaty flavor at 0.l ppm Meaty, sour,floral aroma; meaty, sour, floral HVP-like flavor at (Ll ppmconcentration Meaty brothy aroma; meaty brothy, nutty aroma with HVPaftertaste at 0.l ppm concentration Cooked chicken-like roastedmeat-like aroma; florallike, fatty flavor at 2 ppm (0.1 ppm threshhold)Roasted meat, sweet aroma; roasted meat vegetable-like flavor at 01 ppmconcentration Sweet, meaty chicken-like aroma; Sulfury meaty flavor at0.5 ppm Meaty, green, creamy aroma; Meaty, green, creamy, nutty flavorat 0.5 ppm (0.1 ppm threshhold level) At 0.1 ppm, heavy roasted aromaand sweet, nutty. roasted taste. At 0.2 ppm, sweet, roasted, hazelnutroasted, sweet aroma and taste. At

0.5 ppm, sweet mouthfeel,

St. John's bread-like notes and hydrolyzed vegetable protein aroma andtaste, with a bloody, meaty, lasting aftertaste.

At 0.1 ppm, sweet meat, nutty, earthy meaty, hydrolyzed vegetableprotein, meat extract aroma and taste.

At 0.05 ppm, meaty, roasted, sweet aroma and taste. At

0.l ppm, sweet, roasted aroma and taste.

At 0.l ppm, sweet, roasted aroma and taste.

Meaty, brown sugar, green walnut aroma; meaty, rubbery, walnut sweetflavor at 2 ppm concentration Roasted meat, liver, sulphury aroma, meatygreen roasted meat liver, sulphury fresh walnut kernal flavor at lMeaty, sweet, HVP, creamy aroma; sweet roasted meat, rubbery flavor at01 ppm,

Thus, the 3-thiafuran derivatives and mixtures thereof according to thepresent invention can be used to alter, vary, fortify, modify, enhance,or otherwise improve the organoleptic properties, including flavor and-/or aroma, of a wide variety of materials which are ingested, consumed,or otherwise organoleptically sensed. The term alter in its variousforms will be understood herein to mean the supplying of imparting aflavor character or note to an otherwise bland, relatively tastelesssubstance, or augmenting an existing flavor characteristic where thenatural flavor is deficient in some regard, or supplementing theexisting flavor or aroma impression to modify the organolepticcharacherein taken to mean those which contribute a part of the overallflavor impression by supplementing or fortifying a natural or artificialflavor in a material, as well as those which supply substantially allthe flavor and/or aroma character to a consumable article.

The term foodstuffs as used herein includes both solid and liquidingestible materials for man or animals, which materials usually do, butneed not, have nutritional value. Thus, foodstuffs includes meats,gravies, soups, convenience foods, malt and other alcoholic ornon-alcoholic beverages, milk and dairy products, nut butters such aspeanut butter and other spreads, seafoods including fish, crustaceans,mollusks and the like, candies, breakfast foods, baked goods,vegetables, cereals, soft drinks, snack foods, dog and cat foods, otherveterinary products and the like.

When the 3-thiafuran derivatives according to the invention are used ina food flavoring composition, they can be combined with conventionalflavoring materials or adjuvants. Such co-ingredients or flavoringadjuvants are well known in the art for such use and have beenextensively described in the literature. Apart from the requirement thatany such adjuvant material be ingestibly acceptable, and thus non-toxicor otherwise non-deleterious, conventional materials can be used andbroadly include other flavor materials, vehicles, stabilizers,thickeners, surface active agents, conditioners, and flavorintensifiers.

Examples of preferred co-flavoring adjuvants are:

Methyl thiazole alcohol (4-methyL5-B-hydroxyethyl thiazole);

Z-Methyl butanethiol;

4-Mercapto-2-butanone;

3-Mercapto-4-pentanone;

LMercapto-Z-propanone;

Benzaldehyde;

F urfural;

F urfural alcohol;

2-Mercapto propionic acid;

Z-Pentene;

Alkyl pyrazine;

Methyl pyrazine;

2-Ethyl-3-methyl pyrazine;

Tetramethyl pyrazine;

Dipropyl disulfide;

Methyl benzyl disulfide;

Alkyl thiophenes;

2-Butyl thiophene;

2,3-Dimethyl thiophene;

S-Methyl furfural;

Acetyl furan;

2,4-Decadienal;

Guiacol;

Phenyl acetaldehyde;

8- Decalactone;

d-Limonene;

Acetoin;

Amy] acetate;

Maltol;

Ethyl butyrate;

Levulinic acid:

Piperonal;

Ethyl acetate;

n-Octanal;

n-Pentanal;

Hexanal;

Diacetyl;

Monosodium glutamate;

Sulfur-containing amino acids;

Cysteine;

Hydrolyzed vegetable protein;

Hydrolyzed fish protein; and

Tetramethyl pyrazine The 3-thiafuran derivatives, or the compositionsincorporating them, as mentioned above, can be combined with one or morevehicles or carriers for adding them to the particular product. Vehiclescan be edible or otherwise suitable materials such as ethyl alcohol,propylene glycol, water and the like. Carriers include materials such asgum arabic, carrageenan, other gums, and the like. The 3-thiafurancompounds according to this invention can be incorporated with thecarriers by conventional means such as spray-drying, drum-drying, andthe like. Such carriers can also include materials for coacervating the3-thiafuran derivatives (and other flavoring ingredients, as present) toprovide encapsulated products. When the carrier is an emulsion, theflavoring composition can also contain emulsifiers such as monoanddiglycerides of fatty acids and the like. With these carriers orvehicles, the desired physical form of the composition can be prepared.

The quantity of 3thiafuran derivatives or mixtures thereof utilizedshould be sufficient to impart the desired flavor characteristic to theproduct, but on the other hand, the use of an excessive amount of thederivative is not only wasteful and uneconomical, but in some instancestoo large a quantity may unbalance the flavor or other organolepticproperties of the product consumed. The quantity used will varydepending upon the ultimate foodstuff; the amount and type of flavorinitially present in the foodstuff; the further process or treatmentsteps to which the foodstuff will be subjected; regional and otherpreference factors; the type of storage, if any, to which the productwill be subjected; and the preconsumption treatment, such as baking,frying, and so on, given to the product by the ultimate consumer.Accordingly, the terminology effective amount and sufficient amount isunderstood in the context of the present invention to be quantitativelyadequate to alter the flavor of the foodstuff.

It is accordingly preferred that the ultimate compositions contain fromabout 0.02 parts per million (ppm) to about 250 ppm of B-thiafuranderivative or derivatives. More particularly, in food compositions it isdesirable to use from about 0.05 ppm to 100 ppm for enhancing flavorsand in certain preferred embodiments of the invention, from about 0.2 to50 ppm of the derivatives are included to add positive flavors to thefinished product. All parts, proportions, percentages, and ratios hereinare by weight unless otherwise indicated.

The amount of 3-thiafuran material or materials of our invention to beutilized in flavoring compositions can be varied over a wide rangedepending upon the particular quality to be added to the foodstuff.Thus, amounts of one or more derivatives according to the presentinvention of from about 2 ppm up to or percent of the total flavoringcomposition can be incorporated in such compositions. It is generallyfound to be desirable to include from about 10 ppm up to about 0.1percent of the 3-thiafuran derivatives in such compositions.

1 l The following examples are given to illustrate embodiments of theinvention as it is preferably preferred to practice it. It will beunderstood that these examples are illustrative and the invention is notto be considered as restricted thereto except as indicated in theappended claims.

EXAMPLE 1 (Preparation of Cis-3-hexene-2,5-dione) [n a 1000 ml roundbottom flask fitted with condenser and magnetic stirrer are placed 200 gof 2,5- dimethoxy-Z,5-dimethyl-2,S-dihydrofuran and 200 ml of a 1%aqueous acetic acid solution. The resulting solution is heated toreflux, refluxed for 2 minutes, cooled with an ice bath to 25C and 625ml of a 2% sodium bicarbonate solution is added. The solution issaturated by addition of 23 g of sodium chloride and extracted withmethylene chloride (1 X 200 ml and 3 X 100 ml). After drying over sodiumsulfate removal of the methylene chloride in vacuo gives 142 g of crudecis-3-hexene-2,5-dione which by GLC analysis is about 90% product havingthe structure:

EXAMPLE ll (Preparation of 3-Thioacetyl-2,5-hexanedione) In 1000 1000 mlround bottom flask fitted with magnetic stirrer, thermometer, additionfunnel and reflux condenser are placed 142 g of crude cis-3-hexene-2,5-dione (ex Example I), 380 ml of ether and 5 drops of piperidine. Thioacetic acid (966g) is added over a period of one hour. When aboutone-eighth of the thio acetic acid is added the solution begins toreflux which continues during the remainder of the addition. Afteraddition is complete the mixture is allowed to stand for 85 minutes.Ether is then removed in vacuo (water asperator) to give 235 g of crudematerial containing about 91% 3-thioacetyl-2,S-hexanedione. Distillationof a 134 g portion of the crude gives 84.5 g of3-thioacetyl-2,5-hexanedione boiling at 86 to 87C at 0.5 corr. NMR, IRand mass spectral analysis confirm the structure:

EXAMPLE [ll (Preparation of 2,5-Dimethyl-3-thioacetyl furan usingisopropenyl acetate) 12 mixtu. L is heated at reflux for an additional20 minutes and then cooled to room temperature during which time 10 g ofsodium bicarbonate is added. After removal of isopropenyl acetate invacuo (35at 20 mm), 50 m] of benzene is then added and the mixture isplaced in a separatory funnel. 10 ml of water is then added to themixture, and when carbon dioxide evolution stops, the aqueous layer isseparated. Concentration in vacuo (35 bath, 20 mm) of the organic phasegives 22.2 g of a dark brown oil. Distillation of the oil gives 1 16.5 gof 2,5-dimethyl-3-thioacetyl furan boiling at 47 48C at 0.25 mm.

EXAMPLE IV (Preparation of 2 ,5-Dimethyl-3 -furanthiol) In a 1000 ml,three-necked flask fitted with thermometer, reflux condenser, nitrogeninlet and mechanical stirrer is placed 35 g of 2,5-dimethyl-3-thioacetylfuran (Produced by the process of Example lll) and 350 ml of 15 sodiumhydroxide solution. The two phase mixture is heated to reflux and after35 minutes becomes homogeneous. The mixture is heated another 20 minutesand cooled to room temperature. The pH of the solution is adjusted to 1by the addition of 310 ml of 20% sulfuric acid and the resulting mixtureextracted with ether (3 X ml). Washing of the combined ether solutionswith saturated sodium chloride solution (4 X 75 ml), drying withanhydrous sodium sulfate and solvent removal in vacuo (25C at 55 mm)gives 26.2 g of crude material. Distillation of the crude material gives17.3 g of 2.5dimethyl-3-furanthiol boiling at 79C at 43 mm. MS, NMR and[R analysis confirm the material as 2,5-dimethyl-3-furanthiol.

EXAMPLE V (Preparation of 3-Mercapto-2,S-hexanedione) To ml of a 2%sodium hydroxide solution in a flask fitted for stirring is added 10 gof 3-thioacetyl-2,5- hexanedione. After stirring for one hour the pH ofthe mixture is adjusted to 5-6 by the addition of dilute 10%)hydrochloric acid, the solution is saturated with sodium chloridesolution and extracted with ether (4 X 25 ml). The ether extracts arecombined, washed with saturated sodium chloride solution (15 ml), driedand concentrated in vacuo to give 6.2 g of crude3-mercapto-2,5-hexanedione. Vacuum distillation gives 2.5 g of3-mercapto-2,S-hexanedione boiling at 57-59C at 0.85 torr. NMR, IR andmass spectral analysis confirm the structure as3-mercapto-2,S-hexanedione.

EXAMPLE Vl (Preparation of 2-Methyl-3-furanthiol) A. 4-Oxo-2-pentanalInto a 5 liter, three-necked flask fitted with mechanical stirrer,thermometer and vacuum take-off are placed 600 g of2-methyl-2,5-dimethoxy-2,5-dihydrofuran and 2400 ml of deionized water.After 20 minutes of stirring at room temperature, the mixture becomeshomogeneous and has a pale yellow green color. Analysis of a sample ofthe reaction mixture by GLC after 3.25 hours shows 22% methanol, 67% 4-oxo-2-pentanal and 9% starting material. Vacuum 26 torr.) is applied tothe reaction mixture while maintaining the temperature of the reactionmixture between 25 and 30C. After 3.25 hours GLC analysis shows 13%methanol, 82% 4-oxo-2-pentanal and 3.2% starting material. The vacuum isremoved and the reaction mixture is allowed to stand at room temperatureovernight. Analysis after standing overnight shows 12.9% methanol, 85%4-oxo-2-pentanal and 2.1% starting material. B.3-Thioacetyl-4-oxo-pentana1 In a liter, three-necked flask fitted withmechanical stirrer, thermometer and addition funnel are placed 2325 mlof the solution obtained in (A) and 2 ml of piperidine diluted in 5 mlof water. To this solution is added a mixture of thiolacetic acid (292.3g) and piperidine (13 ml) over a 20 minute period. After standing anadditional minutes, ml of concentrated hydrochloric acid is added, theresulting mixture poured into a separatory funnel and the oil layerremoved. The aqueous layer is extracted with benzene (500 ml) andmethylene chloride (2 X 500 ml). The benzene extract is combined withthe oil layer and the mixture is dried over sodium sulfate. Themethylene chloride extracts are combined and dried over sodium sulfate.Solvent removal in vacuo (4045 bath at 15 torr.) gives 414.5 g of crudeoil from the benzene extract and 172.5 g of crude oil from the methylenechloride extracts. The crude 3-thioacetyl-4-oxo-pentanal is used as-is"in 1 next step. C. 2-Methyl-3-thioacetyl furan In a 12 liter,three-necked flask fitted with stirrer, reflux condenser, thermometerand addition funnel are placed 2950 ml of isopropenyl acetate and 2 mlof concentrated sulfuric acid. The mixture is heated to reflux and asolution of crude 3-thioacetyl-4-oxo-pentanal (587 g)(obtained in Part(B) supra) in 1,170 ml of isopropenyl acetate is added over a 35 minuteperiod. After refluxing an additional 40 minutes sodium bicarbonate (35g) is added and removal of excess isopropenyl acetate in vacuo iscommenced. The pressure is gradually decreased from 200 to 30 torr. asthe temperature of the reaction mixture drops from 90 to 30C at whichtemperature it is maintained until the volume of the reaction mixture isabout 1500 ml. The material is further concentrated in vacuo (bathtemperature 50 C and 5 torr.) to form a dark brown oil. The concentrateis diluted with 750 ml of benzene and washed with 250 ml of water. Afterdrying over sodium sulfate solvent removal in vacuo (40-50C bathtemperature and 10 mm) gives 647 g of a dark brown oil. Distillation ofthis oil gives 26.8 g of material boiling at 6770C at 1.1 mm which is62% 2-methyl-3-thioacetylfuran. Redistil lation gives 150 g of2-methyl-3-thioacetylfuran of 86% purity determined by GLC boiling at7l-76C at 5.8 to 6.2 mm Hg. pressure. D. Hydrolysis of 2-Methyl-3-thioacetylforan to 2-methyl-3-furanthiol A 5% solution (1500 ml) ofsodium hydroxide in water is heated to reflux under nitrogen. Whenreflux commences 151 g of 2-methyl-3-thioacetylfuran is added over a 15minute period. After 5 minutes heating is stopped and the mixtureallowed to cool. When the temperature reaches 30 C, 258.1g of sodiumdihydrogen phosphate monohydrate and 10 ml of acetic acid are added.After the salt is dissolved the mixture is extracted with methylenechloride (3 X 250 ml). After drying the methylene chloride extracts byfiltration through sodium sulfate and washing the sodium sulfate with100 ml of methylene chloride, the combined methylene chloride solutionsare concentrated in vacuo (30 at mm) to yield 94.8 g of crude2-methyl-3- furanthiol Distillation gives 64.6 g of2-methyl-3-furanthiol boiling at 5556 at 41-42 mm.

EXAMPLE V1] (Preparation of 2-Thioacetylfuran) A. Preparation of2-Butene-1,4-dial A mixture of 2,5-dimethoxy-2,S-dihydrofuran (20 g),water ml) and acetic acid (3 drops) is stirred for 105 minutes at roomtemperature, 22 minutes at 40C and minutes between 60 and 75C. GLCanalysis at this point indicates 15.7% starting material and 83.5%2-butene-1,4-dial The mixture is cooled to 25C and sodium bicarbonate(0.3 g) is added. B. Preparation of 3-Thioacetyl-1,4-butanedial To theaqueous solution obtained in SSA, supra, is added 10 g of thiolaceticacid during a 14 minute period. During the addition, the temperature iskept below 30C by intemiittent application of a cooling bath. After 110minutes, the reaction mixture is extracted with methylene chloride (3X X35 ml). The combined methylene chloride extracts are dried and thenconcentrated in vacuo to give 17.3 g of yellow oil containing about 80%2-thioacetyl-1,4-butanedial. The compound is identified through massspectral, NMR and IR analysis as having the structure:

M.S. No molecular ion; remaining peaks in decreasing intensity 43, 29,27, 45, 55, 60, 84, and 142 m/e units.

NMR (CDCl ):8, 2.38, (s,3); 3.02, (multiplet 2J=10H,); 4.46,(t.l,.l=l0H,); 9.40, (s,1); and 9.68, (s,l) ppm.

IR (thin film) 2850, 2750, 1720, 1700 (shoulder). 1388, 1352, 1132 and958 cm C. Preparation of 3-thioacetylfuran In a 500 m1 flask fitted withmechanical stirrer, reflux condenser, addition funnel and thermometerare placed 109 ml of isopropenyl acetate and 0.2 ml of concentratedhydrochloric acid. The resulting mixture is heated to reflux and, whenreflux commences, a solution of crude 2-thioacetyl-l ,4-butanedial(produced in $813, supra) in 70 ml of isopropenyl acetate is added overa 31 minute period while maintaining reflux. The mixture is heated atreflux for 15 minutes afier addition is complete. After cooling to 25C,sodium bicarbonate (2.4 g) is added and the mixture stirred for 20minutes. The mixture is concentrated in vacuo and 60 ml of henzene and25 ml of water are added. The benzene layer is separated, washed withsaturated sodium bicarbonate solution (5 X 25 ml), dried with sodiumsulfate and concentrated in vacuo to give 14.7 g of an oil. Vacuumdistillation gives 1.24 g of 97.5% pure 3-thioacety1furan. Massspectral, NMR and IR analysis confirm the structure as3-thioacetylfuran.

Mass spectrum, molecular ion, then peaks in decreasing intensity; 142,43, 100, 45, 69, 71, 72 and 73 m/e units.

NMR (CDCl;,) 82.34 (s,3), 6.38 (d,1,J=ll-I,) and 7.46 (m,2,.l=lH,) ppm.

"1 (thin film) 3l20, 1710, 1495, 1355, H97, 1147), I110, I072, I010,953, 940, 870 and 795 cm.

EXAMPLE VIII The following formulation is prepared:

Ingredient Parts by Weight Liquid hydrolyzed vegetable protein 90 4Methyl-beta-hydroxy-ethyl-thiazole 5 Tetrahydro thiophene-Ii-one lFurfuryl mercaptan 0.01 2-Nonenal 0.50 Difurfuryl disulfide .49Dirnethyl sulfide 0.50 Methyl mercaptan 0.50 2,5-Dimethyl-3-thiobenzoylfuran 2.00

EXAMPLE IX The following formulation is prepared:

Ingredient Parts by Weight Liquid hydrolyzed vegetable protein 904-Methyl-beta-hydroxy-ethyl-thiazole 5 Tetrahydro thiophene3one lFurfuryl mercaptan 0.01 Z-Nonenal 0.50 Difurfuryl disulfide .49Dirnethyl sulfide 0.50 Methyl mercaptan 0.50 2,5-Dimethyl-3-thiohexanoylfuran 2.00

EXAMPLE X Preparation of 2,5-Dimethyl-3-thio-2-ethylbutyryl)-furan 29 gof 2,5-dimethyl-3-furan thiol (0.226 moles is dissolved in 200 cc ofdiethyl ether and charged to a 500 ml reaction vessel with 17.8 g ofpyridine 0.226 moles). Alpha-ethyl-n-butyryl chloride (30.5 g) (0.226moles) is dissolved in 100 ml of ether and the alpha-ethyl-nbutyrylchloride solution is charged slowly to the reaction vessel over a periodof [5 minutes. The reaction mass is then stirred for three hours andallowed to remain at room temperature for a period of 72 hours.

The reaction mass is then poured into 500 ml of water thereby creatingtwo phases; an upper ether layer and a lower aqueous phase. The etherlayer is washed with 500 ml of 4% hydrochloric acid followed by 500 mlof saturated sodium bicarbonate solution. The ether layer is then driedover anhydrous sodium sulfate and concentrated to yield an orange oil,crude 2,5-dimethyl-3-thio-( 2-ethyl-butyryl -furan.

The crude material is then distilled at a vapor temperature of 8788C anda pressure of 0.55 mm Hg, yielding l6.6 g of product, confirmed by IR,NMR and mass spectral analysis to have the structure:

Mass Spectral Analysis: Molecular Ion, then in descending intensity:226, 43, 71, I28, 99, 41, 39, 127 We.

NMR Spectrum (CDCl 5.91, (s, l): 3.62, (m, l); 2.25, (5,3); 2.22, (5,3);L64, (m,4); 0.95, (t,6) ppm.

EXAMPLE X] Preparation of 2-Methyl-3-thio-( 2-ethylbutyryl)-furan Into a500 m] reaction flask equipped with stirrer, thermometer and refluxcondenser, a solution of 29 g of 2-methyl-3furanthiol (0.255 moles)dissolved in 195 m] of diethyl ether is added. 20.2 g of pyridine (0.255moles) is then added to the reaction vessel. 34.5 g ofaIpha-ethyl-n-butyryl chloride (0.255 moles) is then dissolved in m] ofdiethyl ether and this solution is slowly added to the reaction vesselover a period of 15 minutes. When the addition is complete, the reactionmass is stirred for a period of 3 hours and then allowed to remain overa period of 72 hours at room temperature.

The reaction mixture is then poured into 500 ml of water yielding twophases; an upper ether layer and a lower aqueous phase. The ether layeris washed with 500 ml of 4% aqueous hydrochloric acid and then 500 ml ofsaturated sodium bicarbonate solution. The ether layer is then driedover anhydrous sodium sulfate and is concentrated to yield 43.8 g of ayellow orange oil.

This oil is distilled at a temperature of 73.5-75C and a pressure of0.45-0.55 mm Hg to yield 39.0 g of 2-methyl-3-thio-( 2-ethylbutyryl)furan having the structure:

Ci l

Mass Spectral Analysis: Molecular lon, then in descending intensity:212, 43, 41, 39, 71, 99, I14, 113 m/e.

NMR Spectrum (CDCI 7.36, (d,l, J=l.8 Hz); 6.30, (d,l,.l=l.8 Hz), 2,48,(m,l)', 2.24, (5,3); 1.64, (m,4); 0.96, (t,6) ppm.

EXAMPLE XI] Preparation of 2,5-Dimethyl-3 -thio( 2-methylbutyryl )-furanInto a 500 ml reaction vessel equipped with stirrer, thermometer, refluxcondenser and addition funnel, 29 g of 2,5-dimethyl-3-furanthiol (0.226moles) dissolved in 200 ml of diethyl ether is added. 27.4 g ofZ-methylbutyryl chloride (0.226 moles) dissolved in 100 ml of diethylether is then charged to the addition funnel. Over a period of 25minutes, the 2-methyl-butyry1 chloride solution in diethyl ether isadded to the reaction mass from the addition funnel with stirring. Whenaddition is complete, the reaction mass is then stirred for a period of2 hours. At the end of this 2'hour period, 17.8 g of pyridine (0.226moles) is added to the reaction mass and the reaction mass is stirredfor a period of 2 hours.

The reaction mass is then poured into 500 ml of water yielding twophases; an upper clear orange ether layer and a lower aqueous phase inwhich pyridine hydrochloride is dissolved.

The ether layer is then washed with 500 ml of 4% hydrochloric acid andthen 500 ml of a saturated sodium bicarbonate solution. The ether layeris then dried over anhydrous sodium sulfate and concentrated, yielding40.8 g of an orange oil which is crude 2,5-dimethyl-3-thio-2-methylbutyryl)-furan. This crude material is then distilled at atemperature of 68-70.5C and a pressure of 0.30 mm Hg, yielding 33.8 g ofproduct, 2,5-dimethyl-3-thio-(2-methylbutyl furan, having the structure:

Mass Spectral Analysis: Molecular lon, then in de scending intensity:212, 128, 57, 43, 85, 41, 39 m/e NMR Spectrum (CDCI 5.92, (s,l); 2.66,(q,1, J=6Hz); 2.28, (s3); 2.23, (s,3); 1.61, (m,2); 1.12, (d,3,J=6Hz);0.95, (t,3,J=6Hz ppm.

EXAMPLE Xlll Preparation of 2-Methyl-3-thio-( 2-methylbutyryl)-furanInto a 500 ml flask equipped with stirrer, thermometer, reflux condenserand addition funnel, 29 g of 2- methyl-3furanthiol 0.255 moles)dissolved in 200 ml of diethyl ether is added. 30.5 g of Z-methylbutyrylchloride (0.255 moles) dissolved in 100 ml of diethyl ether is thenadded to the addition funnel. The 2-methylbutyryl chloride solution isthen added to the reaction mass, dropwise, over a period of minutes fromthe addition funnel. 20.2 g of pyridine (0.255 moles) is then added tothe reaction mass and the stirring is continued for another 10 minutes.When addition is complete, the reaction mass is stirred for a period of80 minutes, after which it is allowed to remain, for a period of 72hours, at room temperature.

The reaction mass is then poured into 500 ml of water yielding twophases; an aqueous phase having pyridine hydrochloride dissolvedtherein, and an ether layer. The ether layer is washed with 500 ml of 4%hydrochloric acid and 500 ml of saturated sodium bicarbonate solution.The ether layer is then dried over anhydrous sodium sulfate andconcentrated to 39.1 g of a yellow oil, which is crude2-methyl-3-thio-(2-methylbutyryl)-furan. This crude material is thendistilled at a temperature of 6566C and a pressure of 0.55 mm Hg,yielding 32.7 g of 2-methyl-3-thio-(2-methylbutyryl)-furan having thestructure:

EXAMPLE XIV Preparation of 2,5-Dimethyl-3-thioisovaleryl furan lnto a 25ml flask equipped with magnetic stirrer, thermometer and additionfunnel, are added:

i. 2,5dimethyl-3-furanfliiol 8 0078 moles) ii. Diethyl ether Afterstirring for 5 minutes, 0.62 g pyridine (0.0078 moles) is added to thereaction mass. After the pyridine addition, 0.94 g of isovalerylchloride (0.0078 moles) is added, dropwise, from the addition funnel,over a 2- rninute period, to the reaction mass. A white precipitateforms which is pyridine hydrochloride. The tem perature in the flaskrises to 35C. After stirring for a 30-minute period, the reaction massis filtered via suction filtration, and the filtrate is concentrated invacuo, to a yellow-orange liquid (containing a small amount of solid)weighing 1.56 g. The major peak is trapped out by GLC and analyzed viamass spectral, NMR and IR analysis. It is confirmed to be2,5-dimethyl-3-thioisovaleryl furan having the structure:

Mass Spectral Analysis: Molecular lon, then in decreasing intensity:212, 57, 128, 93, 85, 212, 127 m/e.

19 NMR Analysis (CDCI Signal Interpretation a ca.

2.45 (m,2) C112 5.84 (5.1) ppm B EXAMPLE XV Preparation of2,5-Dimethyl-3-thioisobutyryl furan into a 25 ml flask equipped withmagnetic stirrer, thermometer and addition funnel, are added:

i. 2,S-dimethyl-3furanthiol 1.0 g

(0.0078 moles) ii. Diethyl ether (anhydrous) ml After stirring for 5minutes, 0.62 g pyridine (0.0078 moles) is added to the reaction mass.After the pyridine addition, 0.83 g isobutyryl chloride (0.0078 moles)is added, dropwise, from the addition funnel, over a oneminute period,to the reaction mass. A white precipitate forms which is pyridinehydrochloride. The temperature in the flask rises to 35C. After stirringfor a 30-minute period, the reaction mass is filtered by suctionfiltration, and the filtrate is concentrated in vacuo to an orangeliquid weighing 1.32 g. The material is analyzed by GLC analysis and themajor peak is trapped and is confirmed by GLC, NMR, [R and mass spectralanalysis to be 2,5-dimethyl-3-thioisobutyryl furan, hav ing thestructure:

Mass Spectral Analysis: Molecular lon, then in decreasing intensity:199, 93, 128, 71, 198, 127 m/e.

NMR Analysis (CDCM):

5,85 (s, 1) ppm EXAMPLE XVl Preparation of 2-Methyl-3-thioisovalerylfuran Into a 25 ml flask equipped with magnetic stirrer, thermometer andaddition funnel, are added:

i. 2-methyl-3-furanthiol 1.0 g

(0.0088 moles) ii. Diethyl ether (anhydrous) 10 m1 After stirring themass for 5 minutes, 0.70 g pyridine is added thereto (0.0088 moles).After the pyridine addition, 1.06 g isovaleryl chloride (0.0088 moles)is added, dropwise, from the addition funnel, over a 3- 10 minuteperiod, to the reaction mass. A white precipitate forms which ispyridine hydrochloride. The temperature of the reaction mass rises to38C. After stirring for a 30-minute period, the reaction mass isfiltered via suction filtration and concentrated in vacuo to give ayellow-green liquid containing a small amount of solid and weighing 1.0g. A sample is analyzed using GLC analysis and found to contain 93%product. The major peak is trapped using GLC and as confirmed by massspectral, IR and NMR analysis is 2-methyl-3-thioisovaleryl furan, havingthe structure:

s \l O 0 Mass Spectral Analysis: Molecular ion, then decreasingintensity: 198, 57, 95, 41, 114, 198, 93, 113 m/e.

NMR Analysis (CDCl,)1

Signal Interpretation 2,21 (s, 3) Ll: 2.46 (d, 2) 43 11,

628 (d, 1) l;[ 7.31(d,1)PPm H 45 EXAMPLE xvn Preparation of2-Methyl-3-(2-thiofuroyl)-furan into a 25 m1 flask equipped withmagnetic stirrer, thermometer and addition funnel, are added:

i. Z-Furoyl chloride 1.14 g

(0.0088 moles) After stirring for 2 minutes, 0.70 g dry pyridine (0.0088

moles) are added to the mass. After the pyridine addition, 1.0 g of2-methyl-3-furan thiol is added, dropwise, from the addition funnel,over a period of two minutes, to the reaction mass. The temperaturerises to 38C and a white precipitate forms (pyridine hydrochloride). Thereaction mass is then stirred for a period of 30 minutes, after whichperiod of time, it is filtered via suction filtration. The filtrate isconcentrated in vacuo to a yellow liquid weighing 1.65 g. This material,as confirmed 65 by GLC, mass spectral, IR and NMR analysis is2-methyl-3thiofu royl furan having the structure:

Mass Spectral Analysis: Molecular Ion, then descending intensity: 208,95, 39, 43, 113 m/e.

NMR Spectrum (CDCl 7.57, (d,l); 736 ((3,1); 7.30, (d,1); 6.51, (q,l);6.33. ((1,1); 2.26, (s,3) ppm.

EXAMPLE XVII] Preparation of 2,5-Dimethyl-3-2-Thiofuroyl)-furan Into a25 ml flask equipped with magnetic stirrer, thermometer and additionfunnel, are added:

i. 2,S-Dimethyl-3-furanthiol 1.0 g

(0.0078 moles) ii. Diethyl ether (anhydrous) ml After stirring for 2minutes, 0.62 g pyridine (0.0078 moles) is added to the reaction mass.After the pyridine Mass Spectral Analysis: Molecular Ion, then indecreasing intensity: 222, 95, 43, 222, 41, 194, 57 m/e.

NMR Analysis (CDCI Signal Interpretation It as 0 3 EXAMPLE XIXthermometer and addition funnel, are added:

i, 2Mcthyl-3-furan thiol 1.0 g

(0.0088 moles) ii, Diethyl ether (anhydrous) 10 ml After stirring themass for 5 minutes, 0.70 g pyridine (0.0088 moles) is added thereto.After the pyridine addition, 1.43 g octanoyl chloride (0.0088 moles) isadded, dropwise, over a 2 minute period, from the addition funnel, tothe reaction mass. A white precipitate forms (pyridine hydrochloride)and the temperature of the reaction mass rises to 38C. After addition ofthe octanoyl chloride is complete, the reaction mass is stirred for aperiod of minutes, after which period it is filtered via suctionfiltration. The resulting filtrate is then concentrated in vacuo givingan amber liquid containing a small amount of solid and weighing 1.30 g.The major component is trapped using GLC and is de termined by IR, massspectral and NMR analysis to be Z-methyl-3-thiooctanoyl furan, havingthe structure:

, Mass Spectral Analysis: Molecular Ion, then in decreasing intensity: 20, 57, 177, 43, l 14, 41, 240 m/e.

NMR Analysis (CDC1 Signal Interpretation 0.85 (m, 3) flu l.38(m,8) 2l41.68 (m, 2) 2- 2.2 (s, 3) C li, 2.57 (d, 2) C l1 6.25 (d, 1) fl7.3003. 1) ppm B EXAMPLE XX Preparation of 2,5-Dimethyl-3-ThiooctanoylFuran Into a 25 ml flask equipped with magnetic stirrer, thermometer andaddition funnel, are added:

i. 2.5-Dimethyl-3-furanthi0l 1.0 g

(0.0078 moles) ii. Diethyl ether (anhydrous) 10 ml 23 The resultingfiltrate is concentrated in vacuo giving an amber liquid weighing 1.63g. The major product is trapped using GLC and is confirmed to be2,5-dimethyl-3-thiooctanoy1 furan by mass spectral, NMR and 1R analysis,having the structure:

Mass Spectral Analysis Molecular Ion, then in decreasing intensity 254,128, 57, 43, 254, 127, 41 m/e.

NMR Analysis (CDCI EXAMPLE XXI Preparation of 2,5-Dimethyl-3-thiobenzoylFuran Into a 50 ml round bottom, three-neck flask equipped with magneticstirrer, ml addition funnel, nitrogen inlet, y-tube and thermometer, 30ml diethyl ether, 1.86 g of anhydrous pyridine (0.0235 moles) and 3 g of2,5-dimethyl-3-furan thiol (0.0235 moles) are 24 Mass Spectral Analysis:Molecular lon, then decreasing intensity: 232, 105, 77, 43, 51.

NMR Spectrum (CDC1 7.95, (m,2); 7.42, (m,3);

5 5.92. (s,1)', 2.26, (5,3); 2.22, (5,3) ppm.

charged. Over a period of 25 minutes, 3.30 g of benzoyl chloride (0.0235moles) is added to the reaction mass with stirring. After the additionof the benzoyl chloride is complete, 6 ml of diethyl ether is added tothe reaction mass, which is then stirred for a period of 40 minutes atroom temperature. At the end of this period of time, the resultantslurry (orange solution and heavy white solid) is filtered throughsodium sulfate. The filter cake is washed with diethyl ether. Thecombined filtrates are concentrated on a rotary evaporator, yielding acrude yellow oil, which is crude 2,5-dimethy1-3-thiobenzoyl furan. Thefilter cake is then washed with npentane (30 ml) yielding a yellowsolution which is then evaporated, yielding a heavy yellow oil. The oilsare combined to yield 4.25 g of crude material which is then distilledat a temperature of 118122C at 0.5 mm Hg.pressure, yielding2,5-dimethyl-3-thiobenzoyl furan, the structure of which is confirmed bymass spectral analysis, NMR analysis and IR analysis to be:

EXAMPLE XXll Preparation of 2,5-Dimethyl-3-thiocinnamoyl Furan In a 250ml flask is placed 5 g of 2,5-dimethyl-3- furanthiol, 40 ml diethylether, 3.08 g pyridine and 6,48 g cinnamoyl chloride. The resultingmixture is permitted to stand for 12 hours. The mixture is then washedwith 17 ml H 0, 17 ml 4% HC1 and 17 ml of saturated NaH CO solution. Theether layer is then dried over anhydrous Na SO and the solvent isremoved in vacuo to give crude 2,5-dimethyl-3-thiocinnamoy1 furan as ayellow crystalline solid. Recrystallization from hexane gives a sampleof 2,S-dimethyl-3-thiocinnarnoyl furan melting a 64-66C, having thestructure:

Mass Spectral Analysis: Molecular lon, then in descending intensity:258, 131, 103, 43, 77 m/e.

NMR Spectrum (CDCl 7.80, (d, l, J=8 Hz); 7.40, (m, 5); 6.70, (d, l, J=8Hz); 5.90, (5,1); 2.12 (s,3); 2.10, (s,3).

EXAMPLE XXII] Preparation of 2,5-Dimethy1-3-thio-(m-toluoyl) Furan In a250 m1 flask is placed 5 g of 2,5-dimethyl-3- furanthiol, 40 ml diethylether, 3.08 g pyridine and 6.03 g m-toluoyl chloride. The resultingmixture is permitted to stand for 12 hours. The mixture is then washedwith 17 m1 H 0, 17 ml 4% HQ] and 17 ml of saturated Nal-l- CO solution.The ether layer is then dried over anhydrous Na SO and the solvent isremoved in vacuo to give crude 2,5-dimethyl-3-thio-(m-toluoyl) furan.Distillation of this residue gives 3.3 g boiling at 123.5C at 0.27 mmHg. pressure, having the structure:

25 Mass Spectral Analysis: Molecular lon, then in descending intensity:246, 119, 43, 91, 127 m/e.

NMR Spectrum (CDCl 7.76, (m, 2); 7.30, (m 2); 5.90, (s, l); 2.43, (s,3); 2.22, (s, 3); 2.20, (s, 3) ppm.

EXAMPLE XXIV Preparation of 2,5-Dimethyl-3-furanthiol/sodium HydroxideSemisolid Mass In a 50 ml three-necked flask equipped with refluxcondenser, magnetic stirrer and thermometer is placed 20 m1 methanol and0.5 g NaOH. The mixture is stirred until homogeneous and then 5.1 g of2,5-dimethyl-3- 3-thiol-(2-methyl pentenoyl) furan having the structure:

Mass Spectral Analysis: Molecular lon, then decreasing intensity: 224,97, 41, 43, 60, 30, 127.

NMR Analysis (CDCl thioacetyl furan is added. The mixture is allowed tostand for two hours and then brought to reflux for 2 hours. Theresulting orange colored solution is concentrated in vacuo to remove themethanol, resulting in an orange semisolid.

EXAMPLE XXV Preparation of 2,5-Dimethyl-3-thio-( 2-methyl PentenoylFuran Into a 100 ml three-neck reaction flask equipped with refluxcondenser, calcium chloride drying tube, magnetic stirrer andthermometer is placed 4.5 g of the 2,5-dimethyl-3-furanthiol/sodiumhydroxide semi-solid mass prepared according to the process of ExampleXXIV. This material is slurried in ml of tetrahydrofuran, resulting inan almost complete solution. The resulting solution is then stirredrapidly. To this solution is added 4.0 g of 2-methyl-2-pentenoylchloride, rapidly, dropwise, over a period of approximately one minute,resulting in a temperature rise of from 25 to 37C and precipitation of awhite solid, sodium chloride.

The reaction mass is analyzed by GLC analysis after five minutes andthirty minutes and both analyses show that the same material has beenproduced (GLC conditions: 8 X 11inch SE-30, programmed 130 to 225C at6/minute; flow rate-50 ml/min.)

The reaction mass is then stirred for a period of one hour at roomtemperature. The solids formed in the mass are removed by means ofgravity filtration and the resulting filtrate is concentrated in vacuoto a reddish orange liquid weighing 5.2 g. This major material istrapped using GLC. Mass spectral, NMR and IR analyses indicate that theresultant material is 2,5-dimethyl- EXAMPLE XXVI Preparation of2-Methyl-3-thiopivaloyl Furan lnto a 25 ml, three-neck reaction flaskequipped with reflux condenser, calcium chloride drying tube, magneticstirrer and addition funnel, the following materials are added:

i. 2-methyl-3-furanthiol ii. Diethyl ether 1.14g(0.0l moles) 10 ml Thecontents of the flask are stirred for a period of five minutes at whichtime 0.79 g (0.01 moles) of dry, distilled pyridine is added. After thecompletion of the pyridine addition, 120 g (0.01 moles) of pivaloylchloride is added, dropwise, from the addition funnel, over a period ofone minute. At that point a pyridine hydrochloride precipitate isformed. The reaction mass is then stirred for a period of 45 minutesafter which time it is heated to reflux (37C) for a period of 1 hour. Atthe end of this time, GLC analysis indicates that the reaction iscomplete. The reaction mass consists of a solid and liquid. The solid isremoved by vacuum filtration, and the filtrate is concentrated in vacuointo a pale-yellow liquid weighing l.5 g. The major material is trappedusing GLC and analyzed using mass spectral, NMR and IR analyses to be2-methyl-3-thiol-pivaloyl furan having the structure:

Mass Spectral Analysis: Molecular lon, then in decreasing intensity:198, 57, 114, 4l, 29, 85, 39.

NMR Analysis:(CDCl;,)

EXAMPLE XXVll Preparation of 2,5-Dimethyl-3-thiopivaloyl Furan Into a 25ml, three-neck reaction flask equipped with reflux condenser, calciumchloride drying tube, magnetic stirrer and addition funnel, thefollowing materials are charged:

i. 2,5-Dimethyl-3-furanthiol 1.28 g

(0.0l moles) ii. Diethyl ester l ml The contents of the flask arestirred for 4 minutes after which time 0.79 g of pyridine (0.01 moles)is added. After the pyridine addition, 1.20 g (0.01 moles) of pivaloylchloride is added, dropwise, from the addition funnel, over a period of1 minute. The reaction mass is then heated to reflux and maintained atreflux for a period of 1 hour (37C) after which time the reaction massis concentrated to an orange liquid weighing 2.5 g. The major componentis isolated by GLC.

NMR, IR and mass spectral analyses yield the information that theresultant product is 2,5-dimethyl-3-thiopivaloyl furan, having thestructure:

Mass Spectral Analysis: Molecular lon, then in decreasing intensity:212, 57, 128, 43, 212, 41, 127.

NMR Analysis: (CDCl -continued NMR Analysis: (CDCI Signal InterpretationH C CH 5.84 (s, l) ppm H EXAMPLE XXVIII Preparation of2,5-Dimethyl-3-thiohexanoyl Furan Into a ml, three-neck reaction flaskequipped with reflux condenser, thermometer, magnetic stirrer andcalcium chloride drying tube, the following materials are added:

i. 2,5-Dimethyl 3furanthiol 3.84 g (0.03

moles) ii. Diethyl ether (anhydrous) 30 ml The contents of the flask arestirred for 5 minutes, after which time 2.37 g (0.03 moles) of pyridineis added. After the pyridine addition, 4.02 g (0.03 moles) of hexanoylchloride is added, dropwise, over a period of 2 minutes. The reactionmass refluxes during the addition of the hexanoyl chloride. After theaddition is complete, the reaction mass is stirred for a period of 1hour at about 38C. At the end of the 1 hour period, GLC analysisindicates that the reaction is virtually complete. The solid pyridinehydrochloride product is removed by suction filtration and the resultingfiltrate is concentrated in vacuo to a reddish-orange liquid weighing5.0 g. The major material present is isolated using GLC.

Mass Spectral, IR and NMR analyses yield the information that thismaterial is 2,5-dimethyl-3-thiohexanoyl furan having the structure:

Mass Spectral Analysis: Molecular lon, then in decreasing intensity:226, 43, 128, 71, 99, I27, 41, 39, 226.

NMR Analysis (CDCl Signal Interpretation 0.88 (L3) CH,CH, 1.32 (m.4)-CH,CH,-CH,CH, 1.66 (m2) 0 -continued NMR Analysis (CDCI SignalInterpretation CCH CH,CH

H,C CH 256 (1,2)

EXAMPLE XXIX The following formulation is prepared:

In gredient Parts by Weight Liquid hydrolyzed vegetable protein 904-Methyl-beta-hydroxy-ethyl thiazole Tetrahydro thiophene-3one lFurfuryl mercaptan 0.01 2-Nonenal 0.50 Difurfuryl disulfide .49 Dimethylsulfide 0.50 Methyl mercaptan 0.50 2,5-Dimethyl-3-thioacetyl furan 2.00

The 2,5-dimethyl-3-thioacetyl furan causes the above formulation to bedistinctly roast meat in character and in aroma and taste. It istypically gravy-like (roast meat gravy). The 2,5-dimethyl-3-thioacetylfuran also imparts a slight nutty note which can be associated with theroast meat gravy.

EXAMPLE XXX The following formulation is prepared:

Ingredient Parts by Weight Liquid hydrolyzed vegetable protein 904-Methyl-beta-hydroxyethyl-thiazole 5 Tetrahydro thiophene3-one lFurfuryl mercaptan 0.01 2-Nonenal 0.50 Difurfuryl disulfide .49 Dimethylsulfide 0.50 Methyl mercaptan 0.50 Z-MethylJ-thioacetyl furan 2.00

EXAMPLE XXXI The following formulation is prepared (butter flavorformulation):

Ingredient Parts by Weight Diacetyl 60.000

Butyric acid 250.000 37.000

C aproic acid -continued Ingredient Parts by Weight Caprylic acid 17.0002.5-Dimethyl3-thioisovaleryl furan 0.004 Acetyl propionyl 2.500 Methylnonyl ketone 0.100 Cyclotene 20.000 Delta decalactone 205.000 Deltadodecalactone 408.396

The 2,5 -dimethyl-3-thioisovaleryl furan in the above butter flavorcomposition at 0.004% adds a sweet creaminess to the butter fulness.Flavoring margarine at 0.04% and approximately the same for bakedproducts puts this application at l to 3 parts per billion.

EXAMPLE XXXII In Royal instant vanilla pudding (ingredients: sugar anddextrose, precooked starch, sodium and calcium phosphates, salt,vegetable shortening, artifical flavor and color, vegetablemonoglycerides, butylated hydroxy anisole, butylated hydroxy toluene,citric acid and corn oil; produced by Standard Brands, Inc., New York,New York) at parts per billion (0.008 grams of 0.1% dilution of2,5-dimethyl-3-thioisovaleryl furan in grams of pudding) a panelevaluation (5 panelists) was performed. The panel of five agreed thatthe pudding was much sweeter with no off character than such puddingwithout the said 2,5-dimethyl-3-thioisolvaleryl furan. The panel of fivealso agreed that the general over-all aroma of the said pudding wasenhanced as compared with the same pudding without the2,5-dimethyl-3-thioisovaleryl furan.

EXAMPLE XXXIII The following formulation is prepared (butter flavorformulation):

Ingredient Parts by Weight Diacetyl 60.000 Butyric acid 250.000 Caproicacid 37.000 Caprylic acid H.000 2,S-Dimethyl-3-thioisovaleryl furan0.004 Acetyl propionyl 2.500 Methyl nonyl ketone 0.100 Cyclotene 20.000Delta decalactone 205.000 Delta dodecalactone 408.396

The 2,5 -dimethyl-3-thioisovaleryl furan in the above butter flavorcomposition at 0.004% adds a sweet creaminess to the butter fullness.Flavoring margarine at 0.04% and approximately the same for bakedproducts puts this application at l to 3 parts per billion.

EXAMPLE XXXIV 31 32 pared to the same chocolate pudding without said 25-lower organic phase is drawn off. The aqueous phase isdimethyl-B-thioisovaleryl furan. extracted with two 100 ml portions ofmethylene dichloride and the organic solutions are combined. The EXAMPLEXXXV organic solution is then dried over anhydrous sodium sulfate andfiltered; and then concentrated in vacuo to a yellow liquid weighing32.7 grams. The major peak of A. Preparation of2-Propyl-2,5-dimethoxy-2,5-dihydro this material determined by GLCcontains 2-propyl- Furan From 2Propyl Furan 2,5-dimethoxy-2,5-dihydrofuran (GIJC conditions: F Reaction and M 5750; 8' X /4 inch; SE-30; 130225C per min.,

Preparation of 2-Propyl-3-thioacetyl Furan O O O lnto a 500 mlthree-necked reaction flask equipped flow rate 8O ml/minute, chart speed0.25 inch per with mechanical stirrer, calcium carbonate drying tubeminute).

and thermometer, the following materials are placed: B. Preparation of4-Oxo-2-heptenal Reaction i. 2-Propyl furan 0 g lnto a 250 mlthree-necked reaction flask equipped (0227 with mechanical stirrer andthermometer the following it. Methanol absolute 180 ml m. Sodiumcarbonate 4741 g materials are added:

(0454 moles) i. Z'PropyI-ZJ-dimethoxy 32.7 g The reaction mass is cooledto l0C using a dry-Ice 2,5-dihydrofuran prepared (0.16 moles) acetonebath. Over a period of 20 minutes, a solution of fi g f w the w 36.3grams of bromine in 70 ml absolute methanol is ii zz 325 added dropwisewhile maintaining the reaction mass at l2C to l 3C. After the additionof the bromine solllfiOl'l, the reaction mass is stirred for L5 hourswhile 40 The reaction mass is stirred for a period of 4 hours atmaintaining same at 10C. 24C. At the end of this period of time, thereaction The reaction mass is then mixed with 450 ml of satumass existsi two h an aqueous upper h d rated sodium chloride solution. Theresulting mixture is an organic lower Phase The aqueous upper phase isuction filtered an t filter Cake is Washed Wiih 100 canted and placedin a 1 liter vessel for the following ml of methylene dichloride. Theresultant filtrate and reaction C Reaction f 4.0 Hepena] with 11,5

washings are placed in a separatory funnel and the aCetic A id R i 5.))L a Q o 0 W +HC-C/ H 3 SH To the stirred aqueous solution produced inPart B, supra, of 4-oxo-2-heptenal is added 0.4 ml piperidine. After thepiperidine addition, 12.4 grams of thioacetic acid is added to thereaction mass over a period of 4 minutes while maintaining the reactionmass at a temperature in the range of 2732C. After the thioacetic acidaddition is complete, the reaction mass is stirred for L hours. Thereaction mass is then placed in a separatory funnel and extracted withI00 ml of methylene dichloride. The methylene dichloride solution isthen separated, dried over anhydrous sodium sulfate and concentrated toan orange oil weighing 23.8 grams. This orange oil is analyzed using GLCand determined to contain two isomers having the above structures.

Mass Spectral Analysis of Trap 1: Molecular lon, then in decreasingintensity: 202, 43, 28, 71, 55, 41, 97, 83 m/e.

Mass Spectral Analysis of Trap ll: Molecular lon, then in decreasingintensity: 202, 28, 43, 71, 99 m/e. D. Preparation of2-Propyl-3-thioacetyl Furan Reaction i. llopropenyl acetate 0.5 ml

ii. Concentrated sulfuric acid The mass is heated to reflux (93C) and,over a period of minutes, while maintaining the reaction masstemperature at 91-93C, a solution of 23.0 grams of the reaction productof Part C in ml of iospropenyl acetate is added from the addition funnelto the reaction mass with stirring. The reaction mass is then stirredand maintained at 91C for a period of minutes at which point 5.0 gramsof sodium bicarbonate is added to the mass.

The isopropenyl acetate cyclization agent is then distilled off at a pottemperature of 80C and a head temperature of 50C at 60 mm Hg pressure.The resulting residue is admixed with ml benzene and 50 ml wa ter. Theresulting mixture is placed into a separatory funnel and the layers areseparated. The benzene layer is filtered through anhydrous sodiumsulfate and is then concentrated in vacuo to a brown liquid weighing 5.0grams. This liquid is distilled through a short path microdistillationapparatus at 100l03C and 0.3 mm Hg pressure, yielding2-propyl-3-thioacetyl furan as confirmed by mass spectral and NMRanalysis.

Mass Spectral Analysis: Molecular lon, then in decreasing intensity:184, 113, 43, 142, 27, 184.

NMR Analysis (CDCl,)

Signal Interpretation 5 1.01 (L3) CH,CH,

[.65 (m2) CH,CH,CH

-CCH= CH,CH, 6.32 (dJ) H H 7.35 ppm (d.l) H

EXAMPLE XXXVI Preparation of 2-Methyl-3-thioisobutylfuran A mixture of1.0 g of 2-methyl-3-furanthiol, 0.70 g of pyridine and 10 ml of diethylether is placed in a flask and 0.93 g of iosbutyryl chloride is added.After standing 30 minutes, the resulting mixture is filtered and thefiltrate concentrated in vacuo to a greenish yellow oil weighing 1.0 g.The product is isolated by preparative GLC. NMR, [R and mass spectralanalysis confirmed the structure of the product as2-methyl-3-thioisobuty- 36 in order to impart to said foodstuff a meatyaroma and taste 2. The process for altering the flavor of a foodstuff ofclaim 1 wherein the 3-furyl thioester compound is 2.5- dimethyl-3-thio(2-ethylbutyryl) furan.

3. The process for altering the flavor of a foodstuff of claim 1 whereinthe 3-furyl thioester compound is 2- methyl-3-thio( Z-ethylbutyryl)furan.

4. The process for altering the flavor of a foodstuff of claim 1 whereinthe 3-furyl thioester compound is 2,5-

dimethyl- 3-thio( Z-methylbutyryl) furan.

1. A PROCESS FOR ALTERING THE ORGANOLEPTIC PROPERTIES OF A FOODSTUFFWHICH COMPRISES ADDING TO SAID FOODSTUFF FROM 0.02 UP TO 250 PPM OF A3-FURYL THIOSETER COMPOUND SELECTED FROM THE GROUP CONSISTING OF:2.5-DIMETHYL-3-THIO(2-ETHYLBUTYRYL) FURAN,2-METHYL-3-THI0(2-ETHYLBUTYRYL) FURAN, AND2,5-DIMETHYL-3-THIO(2METHYLBUTYRYL) FURAN IN ORDER TO IMPART TO SAIDFOODSTUFF A MEATY AROMA AND TASTE.
 2. The process for altering theflavor of a foodstuff of claim 1 wherein the 3-furyl thioester compoundis 2,5-dimethyl-3-thio(2-ethylbutyryl) furan.
 3. The process foraltering the flavor of a foodstuff of claim 1 wherein the 3-furylthioester compound is 2-methyl-3-thio(2-ethylbutyryl) furan.
 4. Theprocess for altering the flavor of a foodstuff of claim 1 wherein the3-furyl thioester compound is 2,5-dimethyl-3-thio(2-methylbutyryl)furan.